I began this experiment with a blue stroke near the top of the paper. I laid another one down and merged it with purple. I made sure that the brush was fully loaded so that I could get some drips. (I like to do that now and then.) I put a red quarter-circle in the left corner, one of the locations that children frequently choose for the sun when drawing a landscape. I made another blue-purple line and rotated the paper 90 degrees so the drips would form a coarse grid. This reminded me of a window. Back in the original orientation, I added orange between the original horizontal blue lines. It looked like the sky at sunset.
I enhanced the window with fingerprints, smudges, bug smears and streamers inside and out.